Volume 79, Issue 11

Recent advances in high-resolution X-ray computed tomography (HRXCT) enable comprehensive qualitative and quantitative analysis of wood microstructure. This study combines micro-CT imaging with advanced segmentation to characterize Moringa oleifera L. stem anatomy. Qualitative analysis revealed distinct tissue boundaries, with grayscale images differentiating xylem vessels (bright) from parenchyma (dark) based on density. Reconstructed 3D volumes showed alternating parenchyma-fiber bands, while watershed segmentation delineated pores and Kuwahara filtering preserved structural details. Quantitative results demonstrated spatial heterogeneity: total porosity measured 22.3 ± 2.9 % versus 2.4 ± 1.9 % to 3.7 ± 0.2 % in ROIs. Pore density varied inversely (0.7 ± 0.3 to 1.4 ± 1.0 μm −3 ), with average pore sizes ranging 0.3 ± 0.6 to 1.9 ± 0.2 μm 2 . Strong correlations existed between porosity and pore diameter ( r  = 0.99) or % area ( r  = 0.95), showing morphology governs void fraction. Parameters exhibited symmetric distributions (skewness ≈ 0) with light tails (kurtosis < 3). CT resolved wall thickness variations (0–15 mm), linking microstructure to mechanical properties. The non-destructive approach provides unprecedented 3D quantification of Moringa wood’s structural adaptations, supporting applications in biomaterials and fluid transport systems.

This study investigates the softening behavior of rosin during heating using variable-temperature low-field nuclear magnetic resonance (LF NMR) technique, aiming to demonstrate the potential of LF NMR in characterizing softening transitions including softening point. The NMR signals from three types of industrial rosins during heating from 30 °C to 140 °C were analyzed by applying both mono- and multi-component interpretation methods to evaluate signal amplitudes and relaxation time distributions. These parameters were used to assess the effect of heating temperature on the softening properties of rosin. The temperature-dependent NMR signal amplitude exhibited characteristic S-shaped growth, from which the temperature corresponding to the inflection point, where the signal amplitude increased most rapidly, was proposed as the softening point of rosin. The softening point values were mathematically determined through Boltzmann function modeling and subsequently compared with those measured using the ring-and-ball method. The LF NMR-derived softening point values showed close agreement with ring-and-ball results with deviation of 0.1–1.7 °C, validating NMR reliability for softening point analysis.

This overview traces the modern history of wood science and technology, particularly from the European perspective. It begins with the early forestry schools in 18th-century Germany, which influenced the founding of similar institutions worldwide. These schools introduced technical subjects, including wood physics, to meet industrial demand, especially from the mining sector. Before formal studies began, early research on wood properties, including moisture relations and strength, appeared in encyclopaedias. With the Industrial Revolution, interest in wood as a construction material grew, linking wood research to engineering and materials science. In the early 20th century, dedicated wood technology institutes marked the birth of wood science as a distinct discipline. Today, key research fields include wood-water relations, mechanical and rheological behaviour, wood modification, and structure-property modelling. The future of wood science lies in sustainability and the efficient use of resources. As interest in renewable, bio-based alternatives to steel and concrete grows, further research on wood functionalisation and modification will be vital. Extensive literature is available for deeper study of advances in wood physics.

Wetting plays a crucial role in evaluating the bonding and coating performance of wood and its products. This study investigates the directional dynamic wettability of Douglas fir ( Pseudotsuga menziesii ) wood, focusing on changes in droplet morphology both in parallel and perpendicular directions to the grain. Wettability was assessed using a contact angle measurement system via the sessile drop method. Contact angle, penetration ratio and surface free energy were analyzed, considering the effects of wood tissue type (earlywood, EW; transition wood, TW; and latewood, LW), droplet volume (9, 12 and 15 μL), and grain orientation. The results demonstrated a significant anisotropic spreading of droplets, with greater spreading observed parallel to the grain. The contact angle was consistently lower in the perpendicular direction, with a difference of approximately 10°. After 60 s, the penetration for a 15 μL droplet was 65.4 %, 48.4 % and 41.5 %, respectively for EW, TW and LW. Surface free energy was found to be 17–24 % higher in the parallel direction compared to the perpendicular direction. Anatomical characterization confirmed that variations in cell wall ratio and surface roughness significantly affected wettability. These findings highlight the directional and heterogeneous wettability of wood, providing valuable insights for improving wood coating, bonding, and related processes.

Basic wood density is vital for forest-based industries, especially pulp production. However, sample saturation time before analysis poses challenges, with variations in sample types and methods leading to inconsistencies. This study evaluated the impact of different methods, sample types, and saturation parameters on Eucalyptus basic wood density and pulp industry metrics. Five Eucalyptus clones ( E. grandis , E. urophylla , and hybrids) from a São Paulo experimental plot were analyzed. Samples included discs and wood chips collected along the commercial stem. Basic density was determined using the hydrostatic balance method, while chips were also analyzed via the maximum moisture content method. Saturation methods significantly influenced density values, with differences of up to 28 kg/m 3 . Tests 2 and 3 reduced saturation time to 6 days versus 9–15 days for other methods. Density differences between wedges and chips appeared only in clone C2, with variations up to 11 kg m 3 . Saturation methods affected wood consumption predictions, ranging from 2 to 263 m 3 /ton of air-dried pulp. Test 3 (vacuum, pressure, and 100 °C) was the most efficient. Findings highlight that sample type, saturation, and methods influence basic density variability, directly impacting pulp production efficiency.

The restoration of ancient wooden architectures demands sustainable strategies to produce antique-style wood that mimics naturally aged wood in both aesthetics and structural integrity. Traditional methods for artificial wood aging face challenges in efficiency, scalability, and environmental impact. This study proposed a green and rapid approach using a formic acid/guanidine hydrochloride deep eutectic solvent (DES) combined with potassium hydroxide (KOH) to accelerate the aging of Castanopsis sclerophylla , a key material in historical wooden structures. This dual-treatment process selectively degrades lignin (5.0 % reduction) and hemicellulose (13.4 % reduction) while preserving cellulose crystallinity, closely replicating natural aging mechanisms. The treated wood exhibits a characteristic concave-convex texture and darkened coloration akin to ancient wood, with minimal mechanical property loss (6.5 % decrease in bending strength, 8.4 % in modulus of elasticity). Crucially, this method operates under mild conditions (80–100 °C, 2–6 h), eliminating toxic reagents and energy-intensive steps. The work provides a scalable, eco-friendly solution for producing high-fidelity antique wood, addressing the urgent need for sustainable materials in cultural heritage preservation and antique-style construction.

Wood is a sustainable material, but its inherent flammability and smoke emissions limit its practical applications. This study proposes a thermo-physical strategy to enhance fire safety by fabricating surface densified wood (SDW). SDW were fabricated via hydrothermal pretreatment (20–80 °C) followed by thermo-densification, yielding samples with varying compression ratios (10–30 %; e.g., SDW 20 -30 %) and deformation stabilities (e.g., SDW 80 -30 %). Cone calorimetry revealed that the densified-surface-layer effectively suppressed heat and smoke release by promoting early char formation, which acted as a thermal and mass transfer barrier. SDW 20 -30 % showed 20 % and 70 % reductions in total heat release (THR) and total smoke production (TSP) within the first 360 s. Further improvements were achieved with enhanced densified-surface-layer’s stability: compared to SDW 20 -30 %, SDW 80 -30 % exhibited 32 %, 14 %, and 22 % reductions in CO yield, THR, and TSP, respectively, and delayed peak heat release rate by 73 s. Correlation analysis indicated that densified-surface-layer’s deformation stability contributed more significantly to fire hazard mitigation than densification degree. Thermal and chemical analyses confirmed increased crystallinity and compositional evolution in the densified-surface-layer, leading to improved thermal resistance. These findings demonstrate a chemical-free approach to improving wood fire safety and offer insights into the development of safer bio-based materials.

This study presents a joining of partially delignified wood treated with a concentrated ZnCl 2 solution (parchmentising) and subsequent calendering similar to the fabrication of vulcanised cellulose paper materials. Spruce and beech wood were partially delignified with sodium chlorite to liberate the cellulose for surface bonding. Microscopic analyses reveal an intimate bond line showing the effectiveness of the adhesive-free joining. The average tensile shear strength was 6.6 MPa for spruce and 4.7 MPa for beech.